<ion-header>
    <ion-navbar>
      <ion-title>图片预览</ion-title>
    </ion-navbar>
  </ion-header>
<ion-content>
    <div class="title-size">{{img.w}} X {{img.h}} (宽X高)</div>
    <div id="preview"></div>
    <!-- <div class="zancun" (click)="save2local()">暂存图片</div> -->
    <button ion-button round class="zancun" (click)="save2local()">暂存图片</button>
</ion-content>